mybatis plus之自定义SQL查询

注解查询

public interface UserMapper extends BaseMapper<User> {
    @Select("select * from user ${ew.customSqlSegment}")
    List<User> selectAll(@Param(Constants.WRAPPER) Wrapper<User> wrapper);
}

使用XML查询

maven 资源

默认只有resources 中的文件最终会解析到target/classes中。
如果我们想要把src/main/java中的文件也被复制到target/classes中

       <resources>
            <resource>
                <!-- 设定主资源目录  -->
                <directory>src/main/resources</directory>
            </resource>
            <resource>
                <!-- 设定主资源目录  -->
                <directory>src/main/java</directory>
                <includes>
                    <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，只处理如下配置中包含的资源类型 -->
                    <include>**/*.xml</include>
                </includes>
                <!-- maven default生命周期，process-resources阶段执行maven-resources-plugin插件的resources目标处理主资源目下的资源文件时，不处理如下配置中包含的资源类型（剔除下如下配置中包含的资源类型）-->
                <excludes>
                    <exclude>**/*.yaml</exclude>
                </excludes>
            </resource>
        </resources>

或者使用maven插件maven-resources-plugin

        <plugins>
            <plugin>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.5</version>
                <executions>
                    <execution>
                        <id>copy-xmls</id>
                        <phase>process-sources</phase>
                        <goals>
                            <goal>copy-resources</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${basedir}/target/classes</outputDirectory>
                            <resources>
                                <resource>
                                    <directory>${basedir}/src/main/java</directory>
                                    <includes>
                                        <include>**/*.xml</include>
                                    </includes>
                                </resource>
                            </resources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>

配置XML

1. 配置mapper路径
   在application.properties配置mapper路径

mybatis-plus.mapper-locations=classpath:*/*Mapper.xml

2. 编写XML文件
   注意: xml文件名和Mapper的文件名必须保持一致。比如userMapper,必须对应着UserMapper.xml否则就会找不到对应绑定

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.dankun.mp.dao.UserMapper">
    <select id="selectAll" resultType="com.dankun.mp.entity.User">
        select * from user ${ew.customSqlSegment}
    </select>
</mapper>

3. 最后别忘记了配置MaperScan注解

@SpringBootApplication
@MapperScan("com.dankun.samples.quickstart.mapper")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(QuickStartApplication.class, args);
    }
}